Transcript of "Tetra presentation"

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Radio Trunking
• Trunking stands for sharing. Whenever resources are in
short supply, they will have to be shared.
• In Radio Telephone Trunking System a fixed number of
telephone lines and radio channels are installed in base and
are shared by large number of remote/ mobile subscribers.
This Radio Telephone Trunking System is commonly known
as Radio Trunking System.
• First trunked radio standard introduced was analogue
MPT 1327 from ROHDE & SCHWARZ
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Advantage of Digital Trunking System over Analogue
Trunking System:
• More reliable
• Flexible
• Have connectivity with internet
• Low noise
Disadvantages of Digital Trunking System over Analogue
Trunking System:
• Only disadvantage is that they have low coverage range as
compared with Analogue Trunking System
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What is TETRA ? TErrestrial Trunked RAdio
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Advanced Digital Radio Communications System for
Public Safety Services, Utilities, Transport, Local
Government, Military
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Operational throughout Europe, Asia-Pacific, Africa, South
America and Middle East
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Standard promoted by ETSI
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Multi-vendor supply / interoperation
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TETRA – The New European Standard for Digital Trunking
TETRA: TErrestrial Trunked Radio
• It is the first truly open digital Private Mobile Radio (PMR)
standard.
• The standard is defined by the European Telecommunications
Standards Institute (ETSI).
• The essential parts of the TETRA standard have been approved
in national votings at the end of 1995 (22 countries voted for the
approval and none against it).
• Emergency Service users have contributed strongly in the
creation of the standard.
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TETRA Traffic case - Private call
• Private call (individual call)
– A call between 2 parties within the TETRA network
– May be either simplex or duplex
– May be either hook signalling or direct set-up
– The mobile may reject or modify some combinations
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TETRA Traffic case - Group call
• Group call
– A call between more than 2 parties
– Call is always simplex, direct set-up
– Only possible if one or more groups have been
attached
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TETRA over IP (ToIP):
• A new development in this field is TETRA over IP (ToIP)
system.
• ToIP system has no central switch
• It has distributed intelligence at each Radio Site that can
process and handle local calls.
• Set up inter-site calls and keep track of the registration
locations of each subscriber.
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Difference between GSM and TETRA System
GSM System
TETRA System
Designed for public cellular
telephony.
Designed for professional mobile
radio applications.
Based on Frequency Division
Multiplication Access (FDMA)
Based on Time Division
Multiplication Access (TDMA) –
Economy on frequency spectrum
Not suitable for emergency services Suitable for emergency services due
(Call set up time ~ a few seconds). to very fast call set up time (300 ms)
Do not maintain privacy and mutual
security.
Maintain privacy and mutual
security.
Direct Mode Operation(DMO) is not
possible.
Direct Mode Operation(DMO) is
possible, which supports voice and
data transmission without a Base
Station between Radio Terminals.
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